Method and apparatus for oil cracking



lDec. 9, 1930. J. H. WELCH 1,784,562

'METHOD AND APPARATUS Fon oIL cnw-KING' Filed July e, 1927l 2Sheets-Sheet l GASOLI NE VA?ORS T0 CDNQE. NSE R PRESSU KE REGULATOR //0fb STACK FUEL OIL VFOKS T0 CONDENSEK REFLUX TANK CHARGING STOCK J- TclSteph H. Welnh Dec. 9, 1930. J. H. WELCH METHOD AND APPARATUS FOR OILCRACKING Filed myY e, 192'? 2 Sheets-Sheet 2 me/nto@ lNSULATIO .W m m auREACTION CHAMBER We lah Patented Dec. 9,v 1930 PATENT I oFFlcE JOBEH H.WELCH, OF TULSA, OKLAHOMA METHOD ,AND Arrm'rus Foa on. cnacxmeApplication led July 6, 1927. Serial No. 2613,85?.y

This invention relates to improvements in method and apparatus forcracking petroleum oils. y

The primary object .of the invention is the provision of an apparatusand method for the cracking and refining of petroleum oils which takesinto consideration not only the pressure andtemperature conditions underwhich cracking and treatment of the hydrol carbons is effected, butwhich also takes into the cracking reaction takes place, in order that amaximum yield of gasoline may be obtained. v A further object of thisinvention is the provision of. improved apparatus for the treatment ofhydrocarbon oils, embodying a novel association of cracking chamber andfurnace and improved means for heating and cracking of`petroleumproducts therein.

A further object Vof the invention is the provision of improved meansfor cracking hydrocarbon oils, and treating the same forl removal ofcarbon and entrained oil from the desired gasoline product. c

Other objects and advantages of this invention will be apparent duringthe course of the following detailed description.

` In the-accompanying drawings, wherein for the purposeo'f illustrationis shown only a preferred embodimentof theinvention,

Figure 1 somewhat diagrammatically illustrates the improved apparatusfor thel cracking and treatment of hydrocarbon oils.

taken through the cracking receptacle or reaction chamber of theimproved apparatus.

Figure 3 is a fragmentary view, partly in section, taken throughthelower portion of the improved reaction chamber, and showing thestructural details thereof.

Figure 4 is a'fragment'ary vertical sectional view taken through animproved type of reflux tank., l Y

Figure 5 is a sectional view taken substantially on the line 5 5 ofFigure 4.

1n the drawings, wherein similar reference characters designatecorresponding parts.

throughout the several views, the letter A may 5@ generally designatethe improved apparatus Figure 2 is a transverse sectional view which maycomprise a heating furnace B; reaction chamber or'cracking receptacle C;reiiux tank D; fractionating or bubble tower or tank E; reboiler Fcooperatively related to the tower E; and acarbon trap G.

It is onefof the principal features of this invention that the timefactor under which the hydrocarbon is subject to heat treatment duringcracking, is considered, and the apl paratus has been designed andarranged acconsideration the time factor during which' cordingly. Duringtest runs it has been found that in a run of about seven hours, that istreatment Aof the same batch of hydrocarbon oils over a period of sevenhours, showed a yieldvof about ten times as much gasoline as y arun ofthirty minutes on the same kindgof mg of approved insulating material,relativeso 1y thinner than the other walls of the furnace B in orderthat heat may readily pass therethrough ffor the purpose of heatinghydrocarbon liquid inv thev reaction chamber C at a crackingtemperature', in a relation to be 85 subsequently mentioned. Thecracking tank or reaction chamber-C preferably comprises a cylindricalshaped tank body 25, which in diameter ,is equal to the distance betweenthe inside surfaces of the furnace walls 12, and which is adapted to beseated in the concave rear wall 18 of the furnace, so that the saidfurnace wall 18 and the side walls 12 cover approximately one-half ofthe circumference of the chamber C for two-thirds of the height thereof,the

.about one-third of its distance above the top wall-11, as illustratedin Figure 1. The exon ternal surfaces of the tank body 25 'are pro videdwith heavy insulation 38. Through the bottom wall 30 of the tank body ispositioned an outflow pipe 31, preferably eccentric of the tank axis,said pipe 31 having a passageway 32 therethrough open at its upper endin the compartment 33 of the tank body 25, at a distance above theinside surface of y the bottom 3() so that the hydrocarbon flows zontalpipe or conduit between the ends of the said pipe 40. In the horizontalpipe 40 is a propeller 41, of any approved construction having a shaft42 extending exvteriorly at one end of the pipe 4() and connected with amotor 43 for driving the same. fIhe pipe 4 0 at its opposite end isconnected with the lower header 45 of a bank of heating tubes 46; thebank -of heating tubes 46, extending from the lower rear corner wherethe header 45 is placed, in asloping relation upwardly towardsthe upperfront corneiof the furnace, where a second or upper header' 48 isiplaced, into which the tubes 46 communicate; the'bank of tubes 46 thusslope upwardly above thefire box or cmpartment to receive heat from theproducts cient relation. c

of combustion in the furnace in the most 'eifr- The charging stockheader, and from there through oneior more substantially horizontalpipes 50 extending along the top of the compartment of the furnace, andentering the chamber 33 ofthe reaction tank C, in the upper end thereof;the saidpipe or pipes 50, in the compartment 33, being upturned at 51and being open-at its upper end and having a wide langedcollar thereon,sloping downwardly, over which the oil spreads and flows in a thin filmas it exits from the pipe 50, to assist in crackinfr.

'areferably above the reaction chamber C 1s a reflux tank D, of aboutone-third the slze 'pprovded with perforations 83. as a, means of thetank or chamber C, the same being of cylindrical formation andpositioned on a vertical axis, and consisting of a metal tank body 60having heavy insulation 61 entirely thereabout. A vapor line or conduit62.ex tends from the topof the tank or chamber C, to a locationintermediate the ends of the reflux tank D, for the purpose of admittingthe hot vapors from the top of the compartpasses throughthe Atubes fromthe lower end lto Vthe upper ment 33 to a location intermediate the endsin the compartment of the tank'D.

The remainder of the apparatus will be described in connection with adescription of the lcycle thru which the hydrocarbon oil passes. Thecarbon trap G is supported on a horizontal axis. The same is providedwith a compartment wherein a coil is positioned, one end of the coil at66 having an exit at one end of the carbon trap tank G and into whichend 66 the hydrocarbon charging oil is pumped or forced, and as ittravels through the coil 65 the same is heated by reason of a countercurrent How of hot residual oils which pass through the conduit trap Gin a relation which will be subsequently described. The charging oil orhydrocarbon material then passes through a conduit 67 to a coil 68 orother apparatus in a heat exchange device 69, and the charging oilenters the reflux tank or tower D at 7 O above the conduit 62. Bypreheating the hydrocarbon charging oil in the carbon trap and one ormore heat exchanges or preheaters60 'of any approved construction, thetemperature of the hydrocarbon charging material at the time that itenters the reiiux tank is preferably 650' F. more or"' less. Thecharging stock or petroleum oil is thus deposited in thecompartment 72,of the ieflux tank D, and settles therein,.and passes through aninsulated conduit 73 located in the bottom of the tank D; the conduit 73extending downwardly andv being connected in the outlet pipe 31 belowthe .reaction chamber'C, as illustrated in Figure 1 of the drawings. Therate of flow or discharge of the heated charging stock from thel refluxtank D is float controlled; a valve 76 being positioned in the conduit73, as illustrated in Figure 1, which is controlled by conventionalfloat means 77 well understood in l the art to which thisinventionrelates, for

the purpose of maintaining the oil at a predetermined level in thecompartment 72, as illustrated in Figure 4 of the drawings.'

Within the compartment 72 of the' reflux tank D is a partition 78,between the con# duits 62 and 70 which enter said tank D, whichsubdivides the compartment 72. and provides a vapor inlet compartment 80to which the vapors are admitted through the conduit 62. The partition78 above the `level of the oil or hydrocarbon in the tank compartment isimperforate, but below the level of oil as indicated at 82, thepartition` 78 is of dividing the vapor entering the compartment 80 thruthe conduit 62; in order that this vapor will be forced through thefresh ing understood that the products of combustion, from the furnace,heat the reaction chamber C to the desired temperature, since theinsulation wall 18 is merely provided as a protection for the tank anddoes not prevent the heating of the hydrocarbon in the tank C, as canreadily be ascertained. The hydrocarbon vapors pass from the top of thetank\C thru the conduit 62 into the reflux tank D as above described,where the vapors are scrubbed in the heated charging stock to free thesame ofy particles of carbon and entrained oil, and the vapors passrabove the level 82 ogfjthe oil, and ride upwardly over the lower surfaceof the funnel shaped wall placed in the top of the reflux tank D; saidvapors passing through conduits 91 cir- .f cumferentially arrangedwithin the funnel 90 adjacent the top thereof; the conduits 91 beingnon-radially and tangentially arranged in the funnel for the purpose ofdirecting vapors within the compartment of the funnel 90 in a tangentialdirection in order that the same may assume a swirlingl motion thereinfor the purpose of releasing entrained droplets of oil by centrifugalaction; the vapors proceeding upwardly and exiting through the pipe 93in the top of the reflux tank D; and Ithe entrained oil or liquidprecipitated in the funnel-90 flowing downwardly and through acondilit'95 into the charging stock in the reflux tank D, as isperfectly apparent Afrom Figure 4 of the drawings.

The vapors from the top of they reflux tank D pass into the conduit 93;a pressure reduction valve being positioned i-n the conv lfluit 93, andthe vapors flow downwardly into the lower endl of .the tower E, y)wherethey are scrubbed of carbonparticles and entrained oil in the samerelation that the vapors initially entering the'reux tank are y treatedin said refiux tank D. Within the lower portion of the fractionating orbubble tower E is placed a partition 102 similar to the partition 78above described, providing a small compartment in the lower portion ofthe tower E wherein the vapors enter thru the conduit 93, and passthrough suitable perforationsiin said partition 102 in a finely dividedcondition into a body of hydrocarbon liquid 105 which is condensed inthe 5 tower E from the vapors passing therethrough. The' vapors passingupwardly through the body of liquid 105 are bafiied l by the -plates 106which are of conventional ractionating tower construction. The vaporspasfis through these trays or bubble plates and come into contact with adephlegmator or knock-out box or device 107 in the top of the tower, soregulated as to condense all liquid hydrocarbon except gasoline of thedesired end point which passes in the vapor phase through a conduit 110in the ltop of the tower E, to any desired condenser or location.

The liquid collected in the bottom of the bubble tower E passes througha conduit 115,

in the-bottom of said tower below the partition 102, said conduit havinga tioat operated valve 116 therein controlled by float apparatus 117 ofconventional construction, which float apparatus 1,17 is associated withthe tower Ekfor operation at the desired level of liquid in the bottomof the tower E, to maintain said level above the partition 102 andinsure the scrubbing of the vapor which enters the tower E, in therelation above described. The liquid withdrawn from the bottom of thetank E may be discharged as distillate to storage.

The residuum oil is drawn from the bottom Iof the reaction chamber Cthrough a bottom outlet 120, thru a pipe carrying a pressure reductionvalve 121, and through a conduit 122 into the top of the reboiler F,which in reality is a heatingtank or compartment for maintaining theliquid in the lower portion of the fractionating or bubble tower E at adesired temperature so' that the vapors entering said tower E will notcondense therein except in the desired relation. The reboiler F receivesthe hot residuum oils from the reaction chamber C, the same passingtherethrough into the compartment 124 of the reboilerv F and exitingthrough Ya conduit 125 into the carbon trap G. In the conduit 122between the reboiler F and reaction chamber lub C is positioned a floatoperated valve 128 operated by means of a float apparatus 129 ofconventional formation placed on the reactionl chamber C for operationat a controlling level of hydrocarbon stock in the reaction chamber, asis readily apparent from Figure 1 of the drawings. The hot residuum oilpassing into the carbon trap is cooled to some therein; the residuumflowing as fuel oil through the conduit 130 to-L'isf'tfor'age; said con;

duit l130 having a Hoa inlled valve therein operated by mea Y A hotresiduum oils-'fin arbon trap; said carbon trap having clean-outmanholes I131 quid level of the in the bottom thereof for the purposeo'ficleann ing carbon out of the same.y

i side of the-tank C, in order to distribute and equalize the heat inthe tank C and thus promote cracking.

It is obvious that the petroleum oil is cycled through the furnace tubebank many times during the treatment of the same, comprisingsubstantially a continuous cycling, with a constant introduction offresh charged stock as above described to take the place of the crackedoil vapors entering the reflux tank.

A convenient capacity for the apparatus is 500 barrels of charging stockdaily, requiring 'a still or tank C approximately 8 feet in diameter and20 feet in height. These dimensions are merely explanatory and can bedeparted from, but with such size apparatus the still C will contain 165barrels of oil with a complete renewal approximately once in sevenhours, that is, the oil is kept cycling through the cracking zone forabout seven hours until thoroughly released of all desirable components.

The operation is highly ellicient because in this still a crackingtemperature is continuously maintained, both in the furnace tube bankand inthe reactionV chamber. rlhe fresh stock is permitted to pass intothe outlet pipe 31 and thus does not interfere with he heffing of theoil in the reaction cham- A continuous egress of carbon or undesirableresiduum takes place in the cracking zone of the reaction chamber, andthus the vertical form of reaction chamber is desirable in the relationof details shown and described, since thereby a concentration of theheavy undesirable residuum is maintained in the bottom of the chamber33, which is continuously removed and does not get into circulation withthe hydrocarbon in the compartment 33, since it stratilies to a certainextent below the upper open end of the outlet conduit 31.

It was above mentioned that the reboiler F is used to heat the liquid105 in the fractionating tower E. In the compartment 124 of the re Yoiler F is placed a spiral coil 150, having one end 151 thereor`extending upwardly through the bottom of the tower E and having Atheother end 152 also extending upward- 1y fthrough the bottom of the towerE; both of said ends 151 and 152 terminating in the body-of liquid 105,with the end 151 opening in the liquid l105 at an eevation below theupper opening in the pipe end 152, thus ins uring that a circulation ofthe liquid 105 in the coil 150 will take place, first downwardly throughthe end portion 151, thence into the coil 150 and spiralling upwardlytherethrough, and exit through the end 162 into the body of liquid 105in the tower E; the liquid as it passes through the coil 150 be ingheated and being discharged in a heated condition in the tower E,maintaining the liquid in the bottom of the tower E at a temperaturesuiciently high to permit of the passing through the liquid of thereaction chamber vapors, without condensation of any of the desirablegasoline fractions.

From the foregoing description of this invention it is apparent that anovel method and novel apparatus has been provided for the treatment ofhydrocarbon materials, in order to providea maximum yield of gasoline.

Various changes in the steps by which the method is carried out,and-changes in the shape, size, and arrangement of parts may be made tothe form of invention herein shown and described, without departing fromthe spirit of the invention Ior the scope of the claims.

I claim:

1. The herein described method of treating hydrocarbons which consist inheating a hydrocarbon at a cracking temperature, withdrawing hydrocarbonfrom the heating zone in the vapor phase, passing the hydrocarbon in thevapor phase in finely divided condition thru a body of heated liquidhydrocarbon, centrifugally acting upon the vapor to release entrainedoil and carbon particles therefrom, passing the lhydrocarbon vaporthrough a heated body of hydrocarbon liquid, fractionating thehydrocarbon vapor to produce a desired hydrocarbon vapor, and condensingsaid hydrocarbon vapor.

,2. In apparatus for cracking hydrocarbons, a furnace, means in thefurnace for heating a body of hydrocarbon liquid, a vertically disposedreaction chamber heated by products of combustion from the furnace,means for passing the said body of hydrocarbon liquid from said heatingmeans first mentioned to said reaction chamber, a reliux tank, means forpassing hydrocarbon vapors from the reaction chamber to the reflux tank,means for heating and passing a second body of heated hydrocarbon liquidinto the reflux tank, means in the reflux tank to pass the hydrocarbonvapors which enter the same from the reaction chamber thru the saidsecond body of heated hydrocarbon liquid fed into said reflux tank,means for feeding the heated hydrocarbon liquid from the reflux tank tosaid heating means first mentioned, a vertically disposed fractionatingtower, means for feeding hydrocarbon vapor from the reux tank into saidractionating tower, means in the fractionating tower to condense some ofthe vapor therein and cause it to separate in the liquid phase in thebottom of the tower,

.said hydrocarbon vapor entering the fracl tionating tower vin finelydivided form intov fractionating tower through said reboiler and backinto the fractionating tower in a heated condition by interchange ofheat in the reboiler, and means for withdrawing hydrocarbon liquid fromthe fractionating tower.

3. In apparatus for the treatmentof hydrocarbon vapors a furnace, a bankof heating tubes in the furnace inclined at an acute angleI to theperpendicular, a vertical tankin heating abutment at a Side of thefurnace to take advantage of products of combustion in the furnace forheating said tank at the furnace side thereof, means for withdrawinghydrocarbon liquid from the tank and passlng it into the lower en d ofsaid tubes, means for passing said hydrocarbon from the top of saidtubes into the top portion of said tank, a reiuX tank, means forwithdrawing vapors from the top of the first mentioned tank and passingit into the reflux tank, means for passing heated hydrocarbon liquidstock into the reflux tank in such relation that the hydrocarbon vaporsentering the refiux tank will pass through said hydrocarbon liquidstock, means for passing the hydrocarbon liquid from the reflux tankinto said means which feeds the said liquid into the lower ends of saidtubes, `and means for withdrawing and condensing hydrocarbon vapors,from said reflux tank.

4. In apparatus for the .treatment of hydrocarbons, a furnace, a heatingarrangement 1n the furnace, a vertlcal reactlon tank 1n heating abutmentat one side thereof with the furnace, conduit means connected with thesaid reaction tank for withdrawing liquid therefrom at a point above thebottom of the tank and passing it into the heating arrangement, Vmeansfor passing hydrocarbons after heating from the heating arrangement intothe upper portion of said reaction tank, a reflux tank, means forwithdrawing vapors from the reaction tank and passing it into the refluxtank, a bubble tower, means for passing the hydrocarbon vapors from there-V flux tank' into the bubble tower, means for withdrawing hydrocarbonvapors from the top of the bubble tower, means for withdraw-if ing heavyresiduum oils from the bottom of the reaction tank, a reboiler to whichsaid residuum oils in heated condition are passed, said bubble towerhaving means therein for maintaining a supply of condensed hydrocarbonliquid therein, means associated with the bubble tower for eirculatinsaid hydrocarbon liquid therein through said` reboiler for heat- .ingthe hydrocarbon liquid in the bubblel tower, and means for passingheated hydrocarbon liquid stock into said reiux tank, the vapor from thereaction chamber passing into the reiiux tank and forced through thehydrocarbon liquid therein, and the vapor from the reflux tank beingforced through the heated hydrocarbon liquid in the bottom 'of saidbubble tower.

5. Apparatus for the treatment of hydrocarbons comprising a furnacehaving a compartment therein, a diagonally sloping bank `of tubes in thefurnace compartment, a lower header for the tubes, an upper header forthe tubes, a vertically disposed cracking tank associated with thefurnace to receive the heat from the compartment thereof at one side ofthe tank, an outlet pipe connected with the cracking tank having anopening within the cracking tank at a point above the .bottomf1 ortionof the crackino tank compartment, means connecting said outlet pipe withthe lower headerfor flow of hydrocarbon liquid from the cracking tankinto the lower header of the bank of tubes, pipe means connecting theupper header of the bank of tubes and having an opening into the upperportionof the cracking tank compartment, a reflux tank above thecracking tank having a vapor conduit connection with the cracking tank,a perforated partition subdividing the reflux tank into a plurality ofcompartments, into one of which the vapor conduit admits vapor from thecracking tank, and means for admitting heated hydrocarbon liquid intothe reiux tank so that the hydrocarbon vapor from the cracking tank mustpass through saill( heated vhydrocarbon liquid in the reflux tan 6.Apparatus for thetreatment of hydrocarbons comprising a furnace having acompartment therein, a diagonally sloping bank of tubes in the furnacecompartment, a lower header for the tubes, an upper header for thetubes, a vertically disposed cracking tank associated with the furnaceto receive the heat from -the compartment thereof at one side of thetank, an outlet pipe connected with the cracking tank having an openingwithin the cracking tank at a point above the bottom pol'- tion` of thecracking tank compartment, means connecting said outlet pipe with thelower header fory flow of hydrocarbon liquid from the cracking tank intothe lower header of the bank of tubes, pipe means connecting the upperheader .of the bank of tubes and having an opening into the upperportion of the cracking tank compartment, a reluxtank above the crackingtank having a vapor conduit connection with the cracking tank, aperforated partition subdividing the reiux tank into a plurality ofcompartments, into one of heated hydrocarbon liquid into the reflux tankso that the hydrocarbon vapor from the cracking tank must pass throughsaid heated hydrocarbon liquid in the reiux tank, and means for passingthe heated hydrocarbon liquid from the redux tank into the outlet pipeand thenceinto the bank vof tubes.

7. Apparatus for the treatment of hydrocarbons comprising a furnacehavinga compartment therein, a diagonally sloping. bank l@ of tubes inthe furnace compartment, a lower header for the tubes, an upper headerfor the tubes, a vertically disposed cracking tankV as- A sociated withthe furnace to receive the heat :from the compartment thereof at oneside of the tank, an outlet pipe connected with the cracking tanklhaving an opening within the cracking tank at a point above the bottomportion of the cracking tank compartment, means connecting said outletpipe with the 2@ lower header for flow of hydrocarbon liquid from thecracking tank into the lower header of the bank of tubes, pipe meansconnecting the upper header of the bankv of tubes and having an openinginto the upper portion of the cracking tank compartment,I a reflux tankabove the cracking tank having a va or conduit connection with thecracking tan a perorated partition subdividing the reflux tank into aplurality of compartments, into oneof an .which the vapor conduit admitsvapor from the cracking' tank, means for admitting heated hydrocarbonliquid into the reflux tank so that the hydrocarbon vapor from thecracking tank must pass through said heated hydrocarbon liquid in thereflux tank, means for passing the heated hydrocarbon liquid from thereflux tank into the outlet pipe and thence into the bank of tubes, andmeans for withdrawing heav residuum oils from the 4@ bottom of the crac'n tank.

' JO EPH H, WELCH.

